Traditionally used for protective or defensive purposes, the sandbag conjures up images of conflict and natural disaster. But building such defences requires team work, and so the sandbag also symbolises community spirit. Harnessing this symbolism, Wonder was designed to be both the product and a portrait of collective action.

At the start of the project, I sent a postcard to every household in the neighbourhood, inviting residents to come and be part of the project by helping to fill the sandbags. The response was amazing. Some people came to fill just one bag; others returned day after day to fill as many as they could.

In contrast with the humble sandbag and the temporary structures it is used to build, the pyramid is a monumental form, often built to honour the powerful. In the case of Wonder, the pyramids honoured the power of collective action and the value of community. Pointing towards the sky, they also invited viewers to reflect on the infinity of the universe.

However, the pyramids weren’t just built as a wonder to be gazed at; they were also intended to be used. Children played on them by day; young people hung out on them during the evening; and at night they were used as platforms for stargazing as part of a series of events organised by Edinburgh’s Royal Observatory.

After several months of intensive use, the hessian bags began to burst and the pyramids started to crumble – the sand returning to the beach from which it was taken.